Dog Collars will fits necks from a 6" neck to a 35" neck. To measure your pets neck, take a soft measuring tape and gently wrap around at the base of their neck.  If you can include that with your order, I can make sure the collar you purchase will fit your pet.  If you are unsure how to measure or would like to order a custom collar, reach out to me in the contact form here and I will be in contact with you as soon as I can.